Molecular/biomarker testing in lung cytology: A practical approach

The increasing comprehension of molecular mechanisms underlying lung cancer and the discovery of targetable genomic alterations has dramatically change the pathological approach to lung cancer, especially non-small cell lung cancer (NSCLC). This unstoppable knowledge has taken pathologists to the leading front on lung cancer management. This is especially relevant in the world of cytopathology where “doing more with less” is a daily challenge. Nowadays with a growing number of predictive biomarkers needed to manage patients with NSCLC, there has been a paradigm shift in care and handling of diagnostic samples. One of the main emphasis and interest relies on the utilization of cytologic samples and small biopsies for not only diagnostic purposes but also for ancillary testing. Moreover, lung cytopathology is in continuous evolutions with implementation of new diagnostic techniques, new tools, and facing new challenges. The goal of this paper will be to provide the reader with the necessary concepts than can be used to exploit the cytological samples in order to use these samples for comprehensive diagnosis and relevant ancillary testing purposes.     

Advances in cytology of lung cancer

Cytopathology has emerged as a promising platform in precision oncology especially after the revolutionary change in our understanding of the concept of lung cancer etiopathogenesis. With increasing use of minimally invasive techniques for sample acquisition, it becomes almost mandatory to utilize precious cytology samples maximally and judiciously by appropriate triaging of the specimen and timely action of the cytopathology team. Existing patient management protocols require accurate morphologic and molecular diagnosis of the lung cancer specimens which needs knowledge about evolving techniques related to specimen procurement, updates of genomic variants of lung cancer and recently developed molecular testing platforms and algorithms which are capable enough to use even miniscule amount of diagnostic material. This review provides a brief knowledge about advances in cytology of lung cancer which are helpful for developing correct clinical management strategies.     

Next-generation sequencing in breast pathology: real impact on routine practice over a decade since its introduction

The diagnosis, histomolecular classes of breast cancers (luminal A, luminal B, HER2-enriched, and basal-like), and accurate prediction of prognosis are commonly determined using morphological and phenotypical analyses in clinical practice worldwide. Therapeutic strategies are mostly based on the disease stage and molecular subclasses of breast cancer. Targeted therapies, such as anti-HER2s, poly-ADP ribose polymerase inhibitors or, to a lesser extent, phosphatidylinositol 3 kinase inhibitors, have substantially improved breast cancer patient prognosis over the past decades. Human epidermal growth factor receptor 2 (HER2) overexpression is widely determined based on immunohistochemistry, while next-generation sequencing (NGS) is currently employed to assess the presence of molecular alterations, including breast cancer gene 1 (BRCA1) and 2 or phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) mutations, which are targets of these new approved therapies. In addition, next-generation sequencing (NGS) can aid the pathologist in challenging situations, such as a diagnostic workup for a metastatic carcinoma in lymph nodes of unknown origin, differential diagnosis of spindle cell tumourtumor in the breast between metaplastic carcinoma, malignant PT and sarcoma, o, as well as determining relatedness between primary breast cancers and recurrences. NGS offers a powerful tool that enables the pathologist to combine morphological analyses together with molecular alterations in challenging diagnostic situations.     

Metastatic gynecologic malignancies: advances in treatment and management

Gynecologic cancers comprise of mostly uterine, ovarian, and cervical malignancies and are responsible for 95,000 new cases annually in the United States. Uterine cancer is the most common and the number of new cases and mortality has been increasing. Cervical cancer has decreased due to screening, early detection, and treatment of pre-invasive cancers. However, ovarian cancer remains the most lethal because of advanced stage at diagnosis and drug resistance. The metastatic spread pattern differs amongst these cancers, with uterine and cervical cancer found mostly in the primary organ and ovarian cancer disseminating throughout the peritoneum and upper abdomen at presentation. The primary treatment of ovarian cancer typically involves surgery followed by systemic therapy for more advanced disease. Previously, systemic chemotherapy with platinums, taxanes, doxorubicin, topotecan, and gemcitabine has been the standard in either upfront or recurrent setting. With molecular and genetic breakthroughs, we now have over eight new indications and five novel biologic therapies including antiangiogenics, poly ADP ribose polymerase inhibitors, and immunotherapies approved over the last 3 years. In this review, we will examine the biology of gynecologic cancer metastasis and focus on new treatment options for these cancers with a focus on ovarian cancer.     

Breast carcinoma: Is molecular evaluation a necessary part of current pathological analysis?

Breast cancer is the most common women cancer and is the second leading cause of cancer-related mortality in women. While the last two decades revolutionized breast cancer treatment with the development and use of therapies targeting steroid receptors and HER2/neu, there are limits to the risk estimation provided by traditional clinicopathologic parameters and IHC. Therefore, there is continued potential for inaccurate risk stratification of breast cancer patients which may lead to over- or under-treatment. In this review, we discuss the latest developments in the area of breast cancer research which have lead to better understanding of the breast cancer mechanisms, provided more accurate risk stratification, and identified potential new treatment targets. Specifically, we review the new dualistic model of breast carcinogenesis, which can inform pathologic diagnosis and tumor grading; we also discuss the intrinsic molecular classification of breast cancer and its impact on diagnosis and treatment; lastly, we compare the most common commercial molecular prognostic and predictive assays, with their respective strengths and weaknesses, and their clinical utility.     

Overview of the molecular carcinogenesis of mouse lung tumor models of human lung cancer

Lung cancer is the leading cause of cancer death worldwide, and the need to develop better diagnostic techniques and therapies is urgent. Mouse models have been utilized for studying carcinogenesis of human lung cancers, and many of the major genetic alterations detected in human lung cancers have also been identified in mouse lung tumors. The importance of mouse models for understanding human lung carcinogenic processes and in developing early diagnostic techniques, preventive measures and therapies cannot be overstated. In this report, the major known molecular alterations in lung tumorigenesis of mice are reviewed and compared to those in humans.     

New Dancing Couple: PD‐L1 and MicroRNA

Lung cancer (LC) is the most common cause of cancer death in the world. A great challenge in treating NSCLC is the discovery of advanced, molecular tools to diagnose the disease in early stages as well as the development of immunotherapy. MicroRNAs are regulatory molecules (~20 nt in length) with the ability to regulate the expression of genes. The recently described PD‐1 and PD‐L1 molecules have great importance for potential use in immunotherapy of many cancers. These molecules are associated with immune checkpoints and provide an opportunity for the treatment of advanced NSCLC patients with synthetic monoclonal antibodies. PD‐L1 expression is strictly associated with microRNA function in lung cancer cells. The group of microRNAs related to PD‐L1 includes, among others, miR‐200, miR‐197 or miRNA‐34. Expression of these molecules may be useful in lung cancer diagnosis, qualification to anti‐PD‐1 or anti‐PD‐L1 antibody therapy and could be a potential therapeutic target. However, studies on PD‐L1‐related microRNAs are necessary to develop advanced targeted molecular therapies.     

Renal cell carcinoma: resistance to therapy, role of apoptosis, and the prognostic and therapeutic target potential of TRAF proteins

Renal cell carcinoma (RCC) is the commonest of the renal neoplasms. Although surgery and cryoablation are successful curative treatments for localized RCC, most patients are diagnosed with advanced or metastatic RCC, which has a poor prognosis. RCC are a heterogeneous set of cancers that have traditionally been classified and staged using cellular characteristics, size, local extension and distant metastases. Current staging systems provide good prognostic information, but it is very likely that the identification of new more accurate and predictive prognostic markers, not currently included in traditional staging systems, will improve the outcome for RCC patients. For this reason, increased knowledge of the underlying molecular characteristics of RCC development and progression is necessary. In most cancers, but especially RCC, deregulated control of apoptosis contributes to cancer growth by aberrantly extending cell viability and facilitating resistance to cancer therapies. Here we present the hypothesis that select members of the tumor necrosis factor (TNF) superfamily, the TNF receptor-associated factors (TRAFs), have a role in RCC apoptosis and may have prognostic significance for RCC. Candidate biomarkers for RCC are few, and the TRAFs may be important inclusions in panels of biomarkers for RCC. TRAFs may also be potential molecular targets for new therapies, either through their ability to promote apoptosis in the cancers themselves, or through their ability to modulate the immune defence against cancer progression. Some support data are presented here for our hypothesis. However, these novel concepts need further careful analysis to allow clinicians and oncologists any assistance for earlier detection of RCC and for characterizing patients with RCC for individualised targeted therapy.     

Indikation und Grenzen des intraoperativen Schnellschnitts im Organbereich Lunge

Recommendations for the diagnosis of lung tumors almost limit the use of fresh frozen sections to the evaluation of resection margins. In pathology pretherapeutic methods for assessment of clinically suspected lung cancer are favored over intraoperative frozen section diagnosis. For the interdisciplinary management of uncertain lung findings diagnostic methods, such as cytopathology and examination of biopsy material are available. The use of rapid on-site evaluation (ROSE) in cytopathology is limited due to the lack of necessary personnel. Diagnosis of unclear pulmonary lesions or distinction of metastases from primary lung tumors by intraoperative frozen sections is therefore limited to exceptional cases that were not resolved by preoperative biopsies. Such rare cases require a common consensus strategy between thoracic surgeons and pathologists in a preoperative tumor board.     

Recent advances in pulmonary cytopathology

During the past five years, advances in pulmonary cytopathology have made possible the achievement of several goals, including the diagnosis of pneumonias in immunocompromised hosts, the detection and localization of occult lung cancers in high-risk cigarette smokers, the diagnosis of lesions of the lungs and chest wall by fine-needle aspiration, and the detection of asbestos exposure by sputum cytologic studies. Significant progress has also been made in the application of cell image analysis to the detection of premalignant bronchial epithelial cells in sputum. For the most part, these advances are based on such well-known cytologic procedures as the preparation of thin and evenly distributed smears, prompt fixation, properly controlled and monitored Papanicolaou staining, and thorough screening of slides. Such diligence in laboratory techniques remains the backbone of excellence in pulmonary cytopathology. Cytologic findings should be interpreted with the clinical features of each case in mind, for the practice of pulmonary cytopathology remains an art as well as a science.     

Matrix metalloproteinase induction of Rac1b, a key effector of lung cancer progression

Lung cancer is more deadly than colon, breast, and prostate cancers combined, and treatment improvements have failed to improve prognosis significantly. Here, we identify a critical mediator of lung cancer progression, Rac1b, a tumor-associated protein with cell-transforming properties that are linked to the matrix metalloproteinase (MMP)-induced epithelial-mesenchymal transition (EMT) in lung epithelial cells. We show that expression of mouse Rac1b in lung epithelial cells of transgenic mice stimulated EMT and spontaneous tumor development and that activation of EMT by MMP-induced expression of Rac1b gave rise to lung adenocarcinoma in the transgenic mice through bypassing oncogene-induced senescence. Rac1b is expressed abundantly in stages 1 and 2 of human lung adenocarcinomas and, hence, is an attractive molecular target for the development of new therapies that prevent progression to later-stage lung cancers.     

The role of molecular analyses in the diagnosis and treatment of non-small-cell lung carcinomas

Non-small-cell lung cancer (NSCLC) subtyping has recently been a key factor in determining patient management with novel drugs. In addition, the identification of distinct oncogenic driver mutations frequently associated with NSCLC histotype and coupled to the clinical responses to targeted therapies have revolutionized the impact of histologic type and molecular biomarkers in lung cancer. Several molecular alterations involving different genes (EGFR, KRAS, ALK, BRAF, and HER2) seem to have a remarkable predilection for adenocarcinoma and specific inhibitors of EGFR and ALK are now available for patients with adenocarcinoma harboring the relevant gene alterations. The efficacy of histology-based and molecular-targeted therapies had a deep impact in (1) re-defining classification of lung cancer (particularly adenocarcinomas) and (2) routine clinical practice of pathologists involved in optimization of handling of tissue samples in order to guarantee NSCLC subtyping with the help of immunohistochemistry and adequately preserve tumor cells for molecular analysis. In agreement with the modern multidisciplinary approach to lung cancer, we reviewed here the diagnostic and predictive value of molecular biomarkers according to the clinical, pathologic, and molecular biologist viewpoints.     

Future directions in cancer research: impact of the completion of the human genome

The sequencing of the human genome will have a major impact on the prevention, diagnosis, treatment, monitoring, and outcome of cancer. Progress will most likely occur in a stepwise fashion with the biggest initial impact in diagnosis and molecular targeting of new medicines. Advances in genomics and proteomics have already resulted in major findings that are facilitating earlier cancer diagnosis and disease stratification. New treatments that target specific pathways are well underway for many cancers and likewise, molecular analyses aimed at finding medicines with reduced toxicities are being conducted. Close interaction with the Food and Drug Administration will be very important to integrate these new technologies into product development and the approval of new medicines and diagnostics. Clearly, we are now approaching the era of personalized medicines in which one has the opportunity to maximize the efficacy and minimize the side effects of the cancer treatments. The ability to translate this new technology into improving cancer patient care and outcomes will require that scientists from academia, industry, and govemment work together closely to develop the framework and standards necessary to maximize the benefit of the human genome project.     

The many faces of SRPK1

Serine–arginine protein kinase 1 (SRPK1) phosphorylates proteins involved in the regulation of several mRNA‐processing pathways, including alternative splicing. SRPK1 has been recently reported to be overexpressed in multiple cancers, including prostate cancer, breast cancer, lung cancer, and glioma. Several studies have shown that inhibition of SRPK1 has anti‐tumoural effects, and SRPK1 has therefore become a new candidate for targeted therapies. Interestingly, in terms of molecular mechanism, SRPK1 seems to act heterogeneously, and has been reported to affect several processes in different cancers, e.g. angiogenesis in prostate and colon cancer, apoptosis in breast and colon cancer, and migration in breast cancer. A recent report adds to this puzzle, showing that the main effect of SRPK1 overexpression in non‐small‐cell lung carcinoma is to stimulate a stem cell‐like phenotype. This pleiotropy might be related to preferential activation of different downstream signalling pathways by SRPK1 in various cancers. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.     

Molecular pathogenesis of precursor lesions of pancreatic ductal adenocarcinoma

Precursor lesions are assuming greater importance in the study of pancreatic ductal adenocarcinoma. As pancreatic cancer is almost universally fatal due to late clinical presentation and biological aggressiveness, characterisation of its precursor lesions may create scope for early diagnosis and improved outcome with conventional therapies as well as the development of novel therapeutic and preventative strategies. Pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous tumours (IPMTs) are thought to be precursor lesions of ductal adenocarcinoma of the pancreas. Recent work has focused on the molecular aberrations associated with these lesions leading to the formulation of a progression model for pancreatic cancer. Progressive histopathological changes along the progression model are associated with aberrations of cell cycle regulatory and growth factor signalling molecules that occur in pancreatic cancer at high frequency and are common to many cancers. Characterisation of these molecular aberrations provides scope for the development of novel diagnostic and treatment strategies that will ultimately impact on the outcome for people who develop pancreatic cancer.     

Cytopathology in the diagnosis,treatment and management of malignant respiratory disease

Lung carcinomas are almost always diagnosed using small samples of cellular material. Diagnostic cytopathology has a major role and, with efficient and thoughtful processing and examination of fine needle aspiration or fluid specimens, it is possible to accurately diagnose and perform a full range of predictive testing. This short piece begins by placing cytopathology within an overall umbrella of cellular pathology and briefly describes recent developments in lung cancer diagnosis and treatment. Cytopathological features of the main relevant tumour types and their differential diagnoses are discussed together with their appearance in commonly encountered specimen types such as those from endobronchial ultrasound. There are suggestions for efficient workflow and illustrations of diagnostic pitfalls. Although some trainees are wary of cytopathology, there is no magic (good or bad) involved and any time spent acquiring a facility with interpretation of these specimens as well as their formalin-fixed counterparts will enhance diagnostic skill and, ultimately, patient care.     

Oncogenic drivers,targeted therapies,and acquired resistance in non-small-cell lung cancer

In the past decade, a shift toward targeted therapies in non-small-cell lung cancer following molecular profiling has dramatically changed the way advanced adenocarcinoma is treated. However, tumor cells inevitably acquire resistance to such therapies, circumventing any sustained clinical benefit. As the genomic classification of lung cancer continues to evolve and as the mechanisms of acquired resistance to targeted therapies become elucidated and more improved target-specific drugs come into sight, the future will see more promising results from the clinic through the development of new therapeutic strategies to overcome, or prevent the development of, resistance for lung cancer patients.     

Brain cancer stem cells display preferential sensitivity to Akt inhibition

Malignant brain tumors are among the most lethal cancers, and conventional therapies are largely limited to palliation. Novel therapies targeted against specific molecular pathways may offer superior efficacy and less toxicity than conventional therapies, but initial clinical trials of molecular targeted agents in brain cancer therapy have been frequently disappointing. In brain tumors and other cancers, subpopulations of tumor cells have recently been characterized by their ability to self-renew and initiate tumors. Although these cancer stem cells, or tumor initiating cells, are often only present in small numbers in human tumors, mounting evidence suggests that cancer stem cells contribute to tumor maintenance and therapeutic resistance. Thus, the development of therapies that target cancer stem cell signal transduction and biology may improve brain tumor patient survival. We now demonstrate that populations enriched for cancer stem cells are preferentially sensitive to an inhibitor of Akt, a prominent cell survival and invasion signaling node. Treatment with an Akt inhibitor more potently reduced the numbers of viable brain cancer stem cells relative to matched nonstem cancer cells associated with a preferential induction of apoptosis and a suppression of neurosphere formation. Akt inhibition also reduced the motility and invasiveness of all tumor cells but had a greater impact on cancer stem cell behaviors. Furthermore, inhibition of Akt activity in cancer stem cells increased the survival of immunocompromised mice bearing human glioma xenografts in vivo. Together, these results suggest that Akt inhibitors may function as effective anticancer stem cell therapies.     

Molecular techniques in cytopathology practice

In the last decade, new molecular techniques were introduced into pathology laboratories. Cytology also benefited from the innovations emerging from this new era. Molecular cytopathology (MCP) can be defined as molecular studies applied on all types of cytological specimens, namely gynaecology cytology, exfoliative non- gynaecology cytology and fine needle aspirates. The development of many new ancillary techniques has paralleled the emergence of clinical cytology as a major diagnostic specialty. Clinical applications of these techniques have been growing in the last decade. The widespread acceptance of liquid-based systems in gynaecological cytology emphasises the relation between cells and molecules. The increased use of morphology and molecular biology in human papillomavirus-induced lesions for example, showed the potential to optimise, in one single brushed sample, diagnosis and research. Cytology samples from serous effusions, the pulmonary tree, urine, and aspirations, among others, are now likely to be studied by different molecular techniques for diagnosis, prognosis, or even assessment of therapeutic targets. In this review, the main published results concerning the application of molecular techniques in different fields of cytopathology are highlighted, and their applications discussed.     

Lung cancer samples preserved in liquid medium: One step beyond cytology

Lung cancer is one of the most common cancer types in men and women worldwide with a high mortality rate. World Health Organization (WHO) classification has accepted biopsy as the primary sample for lung cancer diagnosis, pathological classification and molecular testing for management of patients, yet, the use of alternative sampling procedures is highly encouraged. Bronchial cytological samples require a less invasive collection technique and may be suitable for pathological and molecular analysis and storage in liquid medium. Furthermore, the molecular analysis of bronchial cytological samples allows the detection of molecular biomarkers, which may be useful for the selection of molecular targeted therapies. Thus, the purpose of this review is to describe the usefulness of bronchial cytological samples preserved in liquid medium from lung cancer patients for pathological diagnosis and molecular investigation.